BACKGROUND:A common problem encountered in veterinary medicine is the euthyroid sick syndrome(ESS(,which refers to a state, where nonthyroidal illness(such as heart diseases)causes suppression of serum concentrations of thyroid hormone without true pathology of the thyroid gland. Chronic valve disease (endocardiosis) is the most common cause of heart failure in dogs. About a third of small-breed dogs older than10years of age are affected by heart diseases especially endocardiosis. OBJECTIVES: The aims of this study were to determine the effects of some acquired heart diseases (endocardiosis , dilated cardiomyopathy and congestive heart failure)on thyroid hormones, some serum biochemical and hematological indices in small breed dogs. METHODS:A total of 50small breed dogs‌ were selected.25 dogs were healthy and 15,7 and 3dogs had endocardiosis, congestive heart failure and dilated cardiomyopathy respectively which were confirmed by historical, physical examination, radiographic, and echocardiographic findings. Thyroid hormones (T4, fT4andTSH) were determined by using commercial canine Elisa kits. Serum biochemical analysis was carried out to determine the levels of creatine phosphokinase, aspartate aminotransferase,troponin I, blood urea nitrogen, creatinine, total protein, albumin, globulin, triglycerides, and cholesterol. Also Hematological indices (RBC,WBC,PCV,Hb and differential leukocyte count)were measured. RESULTS: One way ANOVA test showed that there were no significant changes in the serum levels of T4and fT4 in patients versus control group (p>0.05) ,only TSH concentration in dilated cardiomyopathy dogs compared to other groups was significant (p<0.05).Observations showed the creatine phosphokinase activity was significantly elevated in endocardiosis and congestive heart failure dogs in comparison with dilated cardiomyopathy and control groups. The serum concentration of protein significantly was decreased in Congestive heart failure dogs compared with endocardiosis and control dogs. Also, in comparison with the control group, serum level of triglycerides was diminished in Congestive heart failure dogs and blood urea nitrogen concentration significantly was increased in endocardiosis dogs compared with control.There were‌ no significant differences in other biochemical and hematological parameters. CONCLUSIONS:In our study,euthyroid sick syndrome or hypothyroidism were not seen in small-breed dogs suffering from heart disease. However in dogs with endocardiosis, increasing of serum creatine phosphokinase activity, could be symbol of complexity of heart disease.

BACKGROUND: On account of the importance of iodine in the synthesis of thyroid hormones, different levels of dietary iodine can affect the occurrence of ascites syndrome in broilers.OBJECTIVES: The current research aimed to investigate the effects of different sources and levels of iodine on performance, carcass traits, ascites mortality, thyroid hormones, and serum biochemical parameters of broiler chickens under cold stress condition.METHODS: This experiment was performed using 375 one-day-old male broiler chickens in a completely randomized design with five treatments, five replications, and 15 birds per replication. To induce ascites, the room temperature was reduced to 15 °C from 14 days and this temperature was maintained until the end of the period. The experimental treatments included: control treatment (basal diet with iodine at the recommended level, 1.25 ppm), basal diet + potassium iodide (KI) with iodine levels (6.25 and 3.75 ppm), and basal diet + calcium iodate [Ca(IO3)2. H2O] with iodine levels (6.25 and 3.75 ppm).RESULTS: The effect of the treatments on the performance indices was not significant throughout the experiment. The lowest percentage of ascites mortality, heart weight, and triiodothyronine (T3) were observed in the treatment (6.25 ppm), which was significantly different from the control treatment (P<0.05). The lowest ratio of right ventricle to total ventricles (RV/TV) was related to potassium iodide treatment (6.25 ppm), which indicated tendency (P<0.10). Chickens receiving higher levels of iodine (6.25 ppm) had higher thyroxine than those receiving lower levels (3.75 ppm) (P<0.05) and showed a lower ratio of triiodothyronine to thyroxine compared to those (P<0.05).CONCLUSIONS: The results of this experiment implied that the use of higher levels of dietary iodine (6.25 ppm), especially as potassium iodide, reduces broiler’s ascites mortality under cold stress conditions.